Patent GB-676896-A (GB)
Title: Improvements in or relating to an automatic nut tapping machine
IPC: B23G1/18
Filed: 1949-11-15
Abstract: 676,896. Feeding nut blanks. SNOW MANUFACTURING CO. Nov. 15, 1949. No. 29199/49. Class 78 (i). [Also in Group XXII] Nut blanks are fed to tapping position in a tapping machine (see Group XXII) from an intermittently-rotated hopper 41 which is mounted on a housing 40 and is arranged to feed the blanks to a guide 77. As shown in Fig. 1. the housing 40 is mounted, together with the tapping-tool 26 and its operating mechanism, on an inclined table 23 on a base 20. The hopper comprises, as shown in Fig. 4, a cup-shaped member with an end wall 45 adjustable to vary the width of the discharge opening 41b, and is mounted on the end wall of the housing 40 by a shaft 52 adapted to be rotated intermittently to agitate the blanks by ratchet mechanism 60 .. 63 acted upon bv the piston 69 of a compressed-air cylinder 70. The blanks are discharged from the hopper into a guide 77 comprising two spaced bars 78, Fig. 5, followed after a short gap by a second narrower guide formed by two spaced bars 80, 81 in which the blanks are tapped. The blanks are fed along the guides by an oscillating finger 95 having an inturned end 95a for engaging the opening in a blank. As a blank passes from the first guide to the second guide, the co-operative effect on the blank of the corner of the bar 80 and the inclined face 85b of a spring-pressed block 85 causes it to rotate into the position shown in Fig. 5. The finger 95 is mounted on a transverse shaft 96 journalled at its ends in a pair of arms 97 Fig. 4, secured upon a rotatable shaft 99 carried by the housing 40 ; a spring 98, Fig. 5, on the shaft 96 urges the finger into contact with the blanks. The feed movement of the shaft 99 is effected against a spring by the co-action of a piston 107, Fig. 4, movable in a compressedair cylinder 108, with an arm 105 on the shaft. An adjustable stop 110, Fig. 5, regulates the feed movement of the finger. The lowermost blank is supported in the second guide by a spring-pressed arm 88 which is pushed aside to release the tapped nut by the pressure of the following blanks. The blank-feeding means are arranged to operate automatically in a continuous cycle which includes successive advances and withdrawals of the rotating tapping tool. With the tool withdrawn, a switch is closed so as to energize a solenoid valve to supply compressed air to the cylinders 70, 108 for agitating the hopper 41 and oscillating the finger 95. As the finger moves through its feed stroke, an arm on the shaft 99 actuates a switch for effecting the advance of the tool, and, at the end of each tapping operation, the tool again actuates the first switch so as to energize a solenoid valve for connecting the cylinders 70, 108 to exhaust ; the tool is then withdrawn and the cycle restarts. Should there be no blanks in the guide 77, the finger 95 will be arrested by engaging a recess in the base of the guide before the arm on the shaft 99 can actuate the switch for moving the tool. An indicator lamp is so arranged in the electric circuit that it will light as soon as the tool starts its forward movement and will continue lighted until the reverse stroke starts ; it will continue to be lighted if the machine stops before completion of a forward stroke or if the finger 95 is arrested by engaging the recess in the guide 77.